Traditional machines comprise a device to hold the ground coffee and the water united in a single unit that also forms the ground coffee infusion chamber; moreover, the machines also include a dosing device for the ground coffee, a moving action mechanism, a boiler, etc.
In the known machines, the container-supply device is removable, for example, for cleaning or maintenance purposes. In fact the container-supply device is the part that is most often soiled because it is always in contact with the ground coffee and because the infusion operation occurs inside this device.
However, washing of this device is extremely difficult, and in certain cases, can also damage the machine. In fact, it is very complicated to obtain access to the internal parts of the container-supply device, and this hinders correct and complete cleaning, especially of the filter.
Moreover, since the container-supply device includes parts that move relative to one another, it is possible that the lubricant is removed, or that certain components are removed or displaced from their correct position during washing operations. The consequences are easy to imagine, both in terms of possible machine damage and in terms of unsatisfactory coffee quality.
A further problem with traditional machines concerns the fact that the machine will produce good quality coffee only when the intervals between one coffee production operation and the next are very short. In the machines for the production of a coffee (in particular domestic versions) that are used with average frequency, the time lapse between the preparation of one cup of coffee and the next is generally too long to guarantee that the internal machine parts, and in particular the water pipes, are still hot. Therefore the quality of the coffee produced by the machine is limited.